I'm more worried that Antpool added ETH and ETC options at some point - *USUALLY* Bitmain doesn't add coins unless they are working on an ASIC for that algorithm, though ETH in particular is "big enough" they might have just added it for the pool fee income.
Going by this thread, Antpool has had an ETH pool since at least May 2016.
https://bitcointalk.org/index.php?topic=1490172.0 Shows how little I pay attention to AntPool.
Guess I can stop worrying now.